#include	<stdio.h>
#define	DATAFILE	"datafile"

FILE	*
open_data(void)
{
	FILE	*fp;
	char	databuf[BUFSIZ];				/* setvbuf makes this the stdio buffer */

	if ((fp = fopen(DATAFILE, "r")) == NULL)
		return(NULL);
	if (setvbuf(fp, databuf, _IOLBF, BUFSIZ) != 0)
		return(NULL);
	return(fp);						/* error */
}
